Operating lever means for breech closing mechanisms



A. A. DICKE 24,648,153 OPERATING LEVER MEANS EON BREECH CLOSING MECHANIsMs Aug. 11, 1953 2 Sheets-Sheet l Original Filed Feb. 9, 1945 EN i. 9mm EN A. A. DIC KE Aug. 1l, 1953 OPERATING LEVER MEANS FOR BREECH CLOSING MECHANISMS 2 Sheets-Sheet 2 Original Filed Feb. 9, 1945 bo nog lo img/10W nom/:www

patented ug.

OPERATING LEVER MEANS ,Foie 1ERE-'ECH CLOSING MEGHANISMS Allen A. Dicke, Montclair," N. J. originar-application February 9,j- 19i5;sra1fNo. l

576,967.y Divided and thisapplicationMay 21, v 1949, `Serial No.- 94,540 Y its frontend, which bolt is helically connected t0- a boltba-rrier, which is slidably mounted in a receiver. i l

Another object is `to provide improved operatingmeansforsuch'a Ygun comprising a hand lever-pivotedfat its upper'and forward end to the'breech v*closing member, such as a bolt carrier, and is pivoted at an intermediate point to a. supporting link which is in turn pivoted to the receiver, whereby movements of said lever and link are such-that the pivoted forward end ofthe operatingV lever may move rectilinearly, as enforced by the path of movement of the breech 'closing member whereby powerful leverage may be applied to the breech closing memberl during the early part of'its lmovement while unlocking and extractinY occur's. Y Y

Another'obje'ct is 'vtoprovide a bolt carrier, the rear'end of which is located forwardly of the rear yof the cartridge magazine, so as to permit ofa corresponding'shortening ofthe receiver, together'with 'the provision of means for keeping closed'thatportion'f the ejection opening located rearwardly ofthe bolt carrier.

Anotler'objct is to" provide Yan improved arrangel'nntffor' detachably connecting such an ope-iatng'lever'to the bolt carrier or other breech closing member' or part thereof, said connection being'acc'es'sible when 'thebreech 'closing memL ber'is in'its extreme rearward'positionsov that the breech closingmembenmay be withdrawn rearwardly lfrom the gun;

Another"object` is 'to providesuch a gun op# erated*-by means of la slidablefore-end and an actionbar'"'connected therewith and also'to the breech closing member by means 'of a conveniently-detachable means.

Another object is to provide an improved'bolt lug abutment collar which is formed separately from-fthe receiver; and the `barrel vso that accurate abutment surfacesjmayY be'gene'rated thereon to assure close'mating engagement between the rear lug faces and the forwardly facing 'abutment faces,l and likewisebetiiveen'theV forward lug faces and the rearwardly facing abutment faces in such abiitinenteollar.'

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Furtherobjects 'and advantages of ythis invention willvbefapparentfrom consideration-of the specification as lillustrated bythe accompanying drawings of possible embodiments of theinvention, in which drawings:

Fig. 1V is -a vertical,l substantially medial; crossselctional -view of -a grile 'intended ,for powerful bottle-neckedcartridges, such as the 30-06 caliber Sprin'geld; cartridge, the operating mechanism .being of the levertype,

Figs. 2, 3 and 4 are cross-sectional viewstaken along the lines 2-'-2, 3-\-3 and 4-4`of-'Fig; l. respectively,

Fig; 5 'is Ia crosslsectional view, partly-fragmentary, taken substantially along the linevr 4--4 but looking rearwardly, the breechmechanism being in its eXtreme rearward position,

Figf is a fragmentary cross-sectional view taken along the line E-G of Fig. 5, looking'in the directionof the arrows,y Y

FigQ'? is a perspective view of thelug-abutment collar, c

Fig. 8 is a perspective viewjofthe-bolt carrier shown in Figs. l to 6, inclusive,

Fig.- -9 is a perspectivejview of the bolt,

FigY 9A is a perspective view ofAa shieldV for the ejection port,

Fig. 1-`0 is-a fragmentary Iside elevation; as viewedA from theleft, of a gun of the lsame type adapted for fore-end operation; andj Fig. v1l is achart showingthe movementof the breech closing member in relation to movements o f the operating lever, and the Jmechanical advantage ratio of said lever -relative -tomsaid membl':

Referring primarily to Figs. 1 to 9, inclusive, thenuineralvill indicates a barrel of more or less usualmconstruction formed with a chamber adaptedhto receive a cartridg e2 2. Thebarrel is attachedto a receive`r 23 bye-any suitable means; such as screw threads 2li. The'receiver has securedtoit -astock .25 of wood or thelikewhich may extend forwardly to provide the fore-end 25a and to enclose vthe lower 'part of the sides of, the receiver. However," in 'thev form shown'in'Fig. 10 the Lst ock 2fterminatesjat the rear end of the receiver, .whichuis entirely exposed, asis usual in sportingries I The receiver isgenerally hollow, being; formed with Aa Vbore ZtlA corresponding generally tofthe desired-diameter of thebolt carrier'Zl from "a point atitsrear open end to the forward end'of thefboltcarrier when the latter is in its extreme forwardY position. The bolt carrierZ'l is formed with two guides orrkeys 21a and 2lb, and the recei'veis formdwith corresponding guideways 28tf'alid`2b, S0-"that the boli? alriei" iS Afleml() slide' axiaily within the receiverbut'is prevented from rotating"thereiiivty Asshown in Fig. 8, these keys are: provided'l with forwardextensi'ons ila and 2lb', respectively, for a purpose tobe described later.

The bolt carrier is formed at its forward end with a cylindrical bore 29 extending about twothirds the length of the bolt carrier and serving to receive the shank portion 30a of a bolt 30, the forward end of which is provided with locking lugs 30111 and 30172. The shank of the bolt is provided with generally helical slots 30c1 and 30c2. The bolt is connected to the carrier by means of a pin 3|, which preferably extends entirely through the bolt carrier and bolt, as shown. The generally helical slots are so located that their rearward ends are in line with the lugs 30131 and 30112. This is desirable because it causes the lugs to be in line with the guide grooves 28a and 2812 so that they may be guided thereby during the rearward excursion of the bolt. This prevents unwanted rotation of the bolt. By having the helical slot located as described, the cross pin 3| may be located in alignment with the guide ribs 21a and 2lb of the bolt carrier, being supported in holes 3| therein. (See Fig. 8.)

This provides a stronger support for the pin 3| and permits making the balance of the walls of the bolt carrier thinner than would otherwise be the case.

In the form shown the bolt is rotated about 60 between its locked and unlocked positions. The lugs are substantially vertical in the locked position and are at an angle of about 30 from the horizontal in their unlocked position (see Fig. 5). This makes a desirable arrangement since the extractor of the construction shown must be located between the lugs and must, at the same time, be so located that the ejection opening will be in a satisfactory location. This is made possible by the arrangement shown, as the ejection opening can be made to face upwardly and slightly to the right (along the line 6-6 of Fig. 5 and as is apparent from Fig. 3). At the same time the generally helical slots 3001 and 3002 are so located that neither one is in line with the extractor 32 (see Figs. 5, 6, and 9). The extractor may be made relatively long and springy if desired. The extractor has a claw 32a which normally overlies the rim of the chambered cartridge and a shank portion 321), the rear end of which is formed with a transverse dovetail 32C fitting in a corresponding slot in the bolt shank. The shank 321) of the extractor lies in a clearance slot in the bolt. Its external dimensions are such that clearance is provided to permit the extractor claw to pass over the cartridge into the extraction groove, and the extractor shank is made sufficiently thin and springy to permit this action.

The forward and rear faces of the locking lugs 30121 and 30122 are preferably made as helical surfaces of quite low pitch so that the helix angle is considerably smaller than the angle of repose. This construction provides a powerful primary extraction, since a comparatively small axial movement is enforced as a result of a rotary movement of some 60. Furthermore, the lead of the helical slots 3001 and 3002 is comparatively great so that the rearward force applied to the bolt carrier provides a rearward extractive pull on the cartridge case many times said force. Furthermore, the rearward force applicable to thebolt carrier is multiplied greatly during the preliminary part of its movement by the lever operating mechanism to be described later. It will also be noted that the extractor rotates with the rotating bolt during the time 0f Primary ex traction so that a torque is applied to the cartridge case, tending to twist the case o ut of the chamber, and thereby facilitating the original, occasionally difcult, part of `the extraction. Since the extractor lies in a groove in the bolt it is well supported against peripheral movement and, therefore, is well capable of applying such an extractive twist to the cartridge case.

The rear part of the receiver bore is shown closed by a closure plug 33, which has a generally cylindrical forward portion fitting into the bore 26 and is provided with lugs 33a capable of being seated in corresponding recesses in the receiver body. In order to remove the closure, it is twisted to the required extent and then withdrawn axially of the bore, that portion of the receiver being preferably formed as shown at 23a. to permit such removal. l

In order to provide for a satisfactory ejection of the red cartridge case, the bolt may be formed as shown with a bore parallel with its axis arranged diametrically opposite the extractor (see Fig. 5), within which is housed an ejector pin 34 preferably held in place by a pin 34a carried by the bolt and received in part in a slot 341) in the ejector pin (Fig. 6). An ejector operating pin 34e is carried by the` closure 33 in such a position that when the bolt is rotated to unlocked position it aligns with the ejector pin 34, therefore. as the bolt carrier approaches the rearward limit of its excursion (as shown in Fig 6), the ejector operating pin 34o passes through an opening 34d in the bolt carrier and its front end stops the movement of ejector pin 34, causing its forward end to throw the cartridge case out of the receiver in a, direction upwardly and to the right, as viewed from the shooter's position.

Firing pin 35 may consist of a shank portion 35a, an enlarged central portion 3519, a forward shank portion 35C, and a striker part 35d which is in line with a small opening 30d in the forward end of the bolt. The firing pin is formed with an elongated opening 35e, through which the cross pin 3| normally passes. Thus the cross pin not only serves to hold the ringpin against excessive rearward movement, but draws the firing pin rearwardly away from `the cartridge as soon as the bolt carrier moves rearwardly. Furthermore, it prevents the ring pin from reaching the cartridge until the action is fully closed. To accomplish the latter purpose, the helical slots 3001 and 301:2 are each formed with a dwell portion 30cm (Fig. 9)` and 30cm (shown in dotted 4lines in Fig- 1) at their forward end. It will be seen further that the bolt will have been icompletely rotated to locked position before the bolt carrier is fully forward, so that the cross pin 3| holds the firing pin away from the cartridge until after the bolt carrier is given an additional forward movement. This dwell construction has the further advantage that rearward thrust of the bolt at the moment of firing, which might occur if excessive head space is present, is not capable of applying a rearward thrust to the cross pin and, therefore, to the bolt carrier which might, under certain conditions, cause the gun to shoot open.

It will be noted from Fig. 6 that the enlarged central portion 3519 of the firing pin is formed with a groove to receive the rear portion of the ejector pin 34.

It will be noted that the rear end of the bolt carrier does not reach to the rear limit of the cartridge magazine and the ejector port, which is amarte designatedG (see-Figs. -1 andf13)-.- In'thisiway it is'possibleito shorten-thereceiver'and therefore toredu'ce the lengthA of ftheentirefarm: This, however,"-leaves' an opening'comprising that part offthe 'ejection'portfto the-rearfofthe bolt carrier; Thiswouldfbefunsightly and would permit the entry .off dirt, twigs, leaves, -etc.,"-whi`ch might interferewith I-theffunctioning of v the arm'. Meansare'providedf to 'close-:this opening which, atthe same time, are so 'arranged -asnot to pre# vent 'thebolt carrier fromfmoving all ythe way back into" engagement ltvith the'reeeiterclosure ca'p'f33." These means" in `theeform shown comprisea cylindricalf'shield 37 (Figs-*1, 4, 5, -`6,*and 9ct). The#internal radius of such shield may preferably correspond to the externalradius "of the`'boltcarrier 21. Itfzisjhowever, provided at its -fiforiw'ard end withflan `inwardlyextending an'ge'31aish`own in dotted lines in Figs; a andl, andirf'cross-se'ctionrinfFig.:6, in perspective in Fig'.- 9a, and i-n full in Fig 10) Thisilangerides upon' a flattened portion 21e formed: at the ltop ofthebolt carrier .21'v `(see` Figs. 1, .3,A 8,y and 10) The lexternal :radius vis slightly greater and the thicknessfof`materialis accommodated by a corresponding cut 31'cfin-the1interiorof the receiver (Figs: 11 and-5) This :out is also* made-sufficiently deeplto' accommodate .an outwardly extending aiigelb formed on the shield. It'willl befseen, therefore, vthat when the breech mechanism is irrlosed-positionthe shield 31 will be drawn into the position shown iii-'Figs -1 and 10, `but that whenfthe 'action is=fullyf open the shield 31 will be pushed vlbaclwardly to fthe position shown in Figi. f6;"this'resultingffrom-the engagement of the forvivard'endy of cut-away` .portion 21o on the bolt carrier with the forwardfedge' of the ilange 31a onthe shield-31. Thismechanism'provides a simple, l cheap, foolproof 'arrangementfor closing thebpening referred-"to and mairesA possible the shortening vof the receiver and, therefore, the shortening of the arm as a whole.

The rear en'dofthe ring`pin 35 -must necessarily /terminate at a point forwardly of the rear ofthe base of the'cartridges in the magazine andlthe hammer must bef4 so arranged that it normally :lies vto fthefrear voffthe` magazine but must be' able to reach 'upwardly and forwardly to'strike the'firing-pin;1 This may YbeL accomplished by :a'pivotedhammer with a'forwardly extendingrnose-but it isfpreferred to' usethe form offconstructionvshown in Fig 1. Therein the hammer comprises `a longitudinally slidable rod dgfpreferably slidablymounted in a tube 4| inclin'ed-fatV anrangle, as-shown.- Within said tube to the rear ofthe hammer is shown 4a coil spring 42shownfasA housed in 'part in -a tube 43 inline with tube 4l; Thesetubes are shown supported byzbeing-:threaded into 'an extension 23p of the receiver 23, which lalso has'a rearward extension 23cfltting: against the stock 25 and secured theretofbyameansof `screw 23d. The tube 43 may conveniently-'serve as 'a Yconnecting point for a stock bolt 44 passing through to the butt of the stock. The-hammer 4is provided-with a Sear notch lila receiving the hook *of a-sear 45 operated'at'will by"a '-trigger, Iwhich is shown as'formed integralffwith fthesear; the sear trigger member being pivoted atflllA and biased counterclockwise by any suitable-spring=f(not shown) It will be Ireadily understood' thatwith the 'hammerin' the position shown-I'in'Fig'. l whenthe' trigger is pulledv the hammer kwill be released f and' will be urged Yforwardly' and upwardly 'by spring T42' until it'strikes tliiflear endof lrin'g pin'l'S 57 (dotted line-posi;

6' tion). Thi'sldrives the' nringlpinlforwardlycausl ing its endf35d to strike andl eXplode-thprimer of the` cartridge 22H When thereafter' theaction is opened by drawing therbolticarrierlrear# wardly, the hammer 40 i'sforoed rearwardly` and downwardly .'by the ri-ing pin' and then'by y the rearface ofthe bolt carrier-until itassum'essublstant'ally the position fshow'n 'irffull flin'es where its forward l'end hasf'esoaped belowthe bottom'of the bolt carrier so th-at-'thebolt caI-"r'ie'r'may con-L tinue its rearward movement un'till it engages lor substantially engages the closure lcap- 335.3 In 'the meantime-the :hook fof the 'sear 1151r isen'gaged in the searnotch an-di `thus iholols1V the-:hammer in retracted p-ositionreadyy for 'ring `the next" shot.

Thefboltlug's l30131 fand `30H2 'may inter-engage with locking abutment f surfaces formed' integral with the receiverfinaccordance withl common practice. However, "the presenti invention fcon templates "the provision i'of' a "separate fmember for this purpose. Saidmember maylftak the form of'abutment,Scollarlllf` shown' in perspective in Figi?. Thiscon'sistsfof a ycontinuous ring portion 48a and-'bifurcated lrearw'ardlyex-V tending memb'ers formed llby' tW'o 'l longitudinal slots 48h' into' which the bolt lugs maypa'ss when they lare in unlocked 'position (Fig-5)? and gen` erally J circumferentially extending recesses-148e within which the 'bolt llugs are-received when the bolt has been tun'edto" locking position (vertical inthe form shownlv lIn ord'erftol-secure rm seating kof the cartridgein-lthechamber and particularly to providellprimary'extraction; vthe surfaces dei-ined Vby *thel {recesses-f 48cl'pre`ferably extend helical-ly. This helix -isofsuehismall advance per 1 turn that 'the' 'angleis Nconsiderably smaller than fthe "angle Aofreposefso 'that no amount of thrust against ntheibolt faceV will cause the bolt 'to' turn tounlo'cked position. Thel parts are so dimensionedthat-the lugs, whichvhave correspondingly-formedi' helical forward and rearward' faces, t rat'her-"closely` insthelrecesses 48e. Therfore,-as-the bolt is rrotated toward locking position'it is "screwed forwardlyto --seat they cartridge 'in thev4 chamber and *when "rotated to unlocking position tliebolt is yserieu/edrear wardly. This will besuicie'nt to cause-primary extraction, ii. e.; to -causethel extractor toI loosen thefired' ease f from 'the chamber- The v abutment collar'` 258Y iis located ina counter bore^in- 'the 'irec'eiver '-(Fifg' 1)l withiitsifforward continuous section '48d surrounding areduced extension 2l-c-on'the barrel. This is preferably fitted quite closely solthat-thelringrdSa will ser-ve to strengthen the chamber against 'the explosion pressure.- Y

The advantage ofl form-ing the flug-engagingsurfaces in a separate'member-,-fsuoh -astalfis that it is difficult or impossible' tofgeneratelproperly formed surfaces'of this type Withinthe'ireceiver.' When madeas shown 1in Fig. 77,':th'e` surfaces maybe generated 'accurately on 1a-'milling machine' by using endmill-vor- 'a-slottihgiattachment. Such a helical surface -is-the only "one 'whereby' relative rotation '-Willproduce' Correspondi'ng` rela'- tive axial movement while maintaining kfull sur-L face Contact. This assures proper seating ofthe cartridge, minimum `head-space,and. easy extrac-`v tion.

The arms shown"asfillustrative of l the 'in-ven# tion are of the box `vvmagazine type,'ri.e., eXtra rounds r22al are v'stored ak box magazine below the bolt carrier, these rounds! being urgedfup-- Wardly by lrneansof a ifo'llowerUZZb Toti the usual: construction urge'clfupwardlyl by 'means -lof "la :spring of usual construction (not shown). To :facilitate transfer of the topmost round to the chamber, a bullet incline 23e is formed forward of the topmost round.

Means for operating the breech action by moving the bolt carrier 21 first rearwardly and lthen forwardly will now be described, attention being rst directed to the lever operating device shown in Figs. 1 to 5J inclusive. The lower left side of the bolt carrier is shown cut away as at to provide clearance for the arm 51a connected to an operating lever generally designated 5|. Said arm 5lc is shown pivoted to the bolt carrier by means of a pivot pin or crossbolt 52 located in a bore in the bolt carrier and biased toward the 4left'side of the gun by means of a spring 52a. This pin is preferably provided with a rearwardly extending pin 52h located in a slot in the rear of the bolt carrier (Figs. 3 and 4). Said pin is for the purpose of moving the pivot pin or crossbolt 52 toward the right for disconnecting the arm 5Ia from the bolt carrier when it is desired to remove the bolt carrier and associated parts from the receiver.

The operating lever 5I includes also a trigger guard portion 5lb and a linger loop 5lc in the usual manner. The operating lever 5l is shown hinged at 53 to a link 54, the forward end of which is hinged as at to the receiver or some member secured thereto.

By means of this construction a powerful leverage is assured during the early part of the movement of the bolt carrier since when the lever 5I is started downwardly it swings about hinge 55. below the bolt carrier (measured perpendicularly to the line of motion of crossbolt 52) a force multiplication of about 6 to l is attained. This applies a powerful rotative effort (torque) to the bolt, due to the high lead of the cam slots 3c1 and 3002. This high torque acting through the small lead helix on the bolt lug faces and their mating surfaces in the member 48 provides an extremely powerful primary extraction.

Unlocking action of the bolt takes place during the comparatively long movement of lever 5l from the full line position to the first dotted line position, during which the most important work is done. During this time the link 54 moves from the full line position toits first dotted line position. Continued movement of lever 5I from the rst dotted line position to the second dotted line position causes the link 54 to move upwardly until it resumes its original (full line) position. The bolt carrier has now achieved its rearmost position where it engages the closure lug 33. During the last part of this motion ejection occurs through the means shown in Figs. 1, 5, and 6, as described hereinabove. At this time the topmost round has jumped upwardly, as is common in guns of this type, to a position ahead of the bolt face, which is now in the position shown in Fig. 6. Return movement of the lever 5l to its rst dotted line position will cause the bolt carrier and bolt to move forwardly to the position Where the cartridge is substantially fully seated in the chamber. Further movement of lever 5l to the full line position serves merely to rotate the bolt to locking position. During this time the bolt moves forward only that slight distance which is caused by the coaction of the helical surfaces on the bolt lug faces and the corresponding surfaces on the abutment collar 48. This movement causes the cartridge to be firmly seated in the chamber. This lever ar- Since this hinge is only a short distance rangement permits the use of a swinging lever to apply rectilinear motion to a breech-closing member with a powerful leverage and by means of a construction which permits the use of a receiver of proper height, and permits vthe construction of a gun of this type with pleasing lines and without unduly large dimensions at the receiver. The lever 5I is also preferably formed with a slot closing shield 5|d of segmental form lying in the plane of arm 5 la. This is used only if the arm 5|a is so formed that in extracting position of lever 5| it will pass into the space in front of the trigger 46. If that occurs a corresponding slot must be formed in the receiver, which slot will be normally closed by the shield 51d.

Fig. 11 shows in chart form the movement of the bolt carrier in relation to the movement of the operating lever. t will be noted that during the rst part of the lever movement there will be only a small movement of the carrier. This gives a high leverage during the time while the bolt is being rotated (or other unlocking action occurs) and while primary extraction occurs. The chart also shows by means of another graph the mechanical advantage of the operating lever for various positions of the lever. The high mechanical advantage is useful not only at the beginning of the stroke of the lever for the purposes stated but is also available at the end of the closing stroke when the cartridge is seated and the locking of the breech occurs.

It will be noted that the mechanism described above comprises a firearm having a chamber, a receiver and a breech-closing unit reciprocating in the receiver, the breech-closing unit including locking means normally engaging with a forwardly facing surface on the receiver when the breech is closed, said breech-closing unit also including a member which is movable rearwardly in the receiver, the first part of such rearward motion serving to disengage the locking means from the forwardly facing surface on the receiver, and an operating lever pivoted at its forward end to said member, said operating lever being also pivoted intermediate its ends to a link whose other end is lpivoted to the receiver. The motion of the operating lever is therefore controlled entirely by the motion of the breech-closing unit in the receiver and by its pivoted connection to the link. The word pivoted as used in this specification and the claims is defined as the connection of two parts to each other in such a way that either part is movable relatively to the other lonly by angular movement about a single axis. Since the lever 5I is pivoted to the longitudinally movable part 21 of the breech-closing unit and also pivoted to the link 54 which is, in turn, pivoted to the receiver at 55, there is provided a two-link and slider kinematic chain linkage wherein the link 54 and the lever 5l are the two links and the breechclosing unit is the slider. Said linkage produces the reltive motion relationships shown graphically in Fig. 11.

While the above-described means serve admirably to provide an excellent bolt-action leveroperated high-powered firearm, many of the parts may be used or readily adapted to make an excellent slide-operated, bolt-action arm. Such an arm is shown in Fig. 10. In this'case the receiver 23 is preferably not covered by the stock, which terminates near the rear end of the receiver. The breech-closing action is operated in this gun by means of a sliding fore-end 60 supported under the barrel 2| by any suitable means,

lsuch as a dovetail, and which serves to operate an action bar 60a, which passes through a correspondingly-shaped recess in the front of the receiver and is formed with an upwardly-extending arm 60h, which is perforated to receive the pin 52, described above in connection with the leveroperated gun.

The operation of this slide-operated arm is similar to that of the lever operated arm. After ring the fore-end 60 is drawn rearwardly by the shooter. This, through bar 60a, arm 60h, and cross pin 52, causes the bolt carrier 21 to be retracted. During this motion cross pin 3l operates in helical cam slots c1 and 3002 to rotate the bolt from locked to unlocked position. During this unlocking movement primary extraction takes place. Further rearward movement causes the completion of the extraction, ejection, and cooking of the hammer. Forward movement of fore-end 60 causes transfer of the topmost round from the magazine to the chamber and rotation of the bolt to locked position. To disassemble a gun of this form the fore-end 60 is merely drawn back to its extreme rearward position, the receiver cap 33 is removed and the user can then reach pin 52h (Figs. 3 and 4) and thereby move pin 52 to the right, disconnecting it from action bar 60a. The bolt carrier with the firing pin, bolt, and extractor can thereupon be moved rearwardly out of the receiver. This also permits cleaning of the barrel from the rear.

It will be noted that the constructions shown and described will serve admirably to accomplish the objects stated above. It is to be understood, however, that the constructions disclosed above are intended merely as illustrative of the invention and not as limiting as various modifications therein may be made Without departing from the invention as dened by a proper interpretation of the claims which follow.

I claim:

1. In a breech-loading firearm, in combination, a receiver formed with an abutment face, a breech closing member including a locking member cooperating with said abutment face, a reciprocable member mounted for movement rearwardly and forwardly in said receiver and so connected with said Ibreech closing member that when moved rearwardly it rst disengages the locking member from the abutment face and then moves said breech closing member rearwardly, and means for reciprocating said reciprocable member comprising a lever pivoted at one end to said reciprocable member and pivoted intermediate its ends to one end of a link whose other end is pivoted to the receiver, whereby the breech closing member serves to guide and control the movement of that end of the lever which is pivoted thereto and a relatively large movement of said lever during the rst part of its movement gives a relatively small movement to the reciprocating member while the locking member is being disengaged.

2. In a breech-loading rearm, in combination, a receiver, a breech closing member reciprocable within said receiver between rearward and forward positions, means pivoted to said breech closing member for reciprocating said breech closing member, and means forming the pivotal connection of said reciprocating means to the breech closing member comprising a crossbolt in the breech closing member spring-projected into an opening in the reciprocating means, and means, accessible when the breech closing member has been moved rearwardly, to move said crossbolt to a position where it may be disconnected from said reciprocating means.

3. In a breech-loading firearm, in combination, a receiver formed with a forwardly facing abutment face, a breech-closing member including a rotary bolt formed with a locking lug engaging with said abutment face when rotated to locking position, a bolt carrier reciprocably mounted in said receiver for movement rearwardly and forwardly therein and helically connected with said bolt so that when the bolt carrier is moved rearwardly the bolt is rst rotated out of locking position to disengage the locking lug from the abutment face and then moved rearwardly with said bolt carrier, and means for reciprocating said bolt carrier comprising an operating lever pivoted at one end to said bolt carrier and pivoted intermediate its ends to one end of a link whose other end is pivoted to the receiver below the point where the lever is pivoted to the bolt carrier, whereby a two link and slider kinematic chain linkage is provided, the two links being the said link and the said operating lever and the slider being said bolt carrier slidable in said receiver, by means of which linkage a relatively large movement of said lever during the rst part of its movement gives a relatively small movement to the reciprocating bolt carrier while the bolt is being rotated to disengage the locking lug from said abutment.

4. In a breech-loading rearm, in combination, a receiver formed with a forwardly facing abutment face, a breech-closing unit reciprocably mounted in said receiver for movement rearwardly and forwardly therein comprising a locking member having a rearwardly facing surface engaging with said abutment face when in locking position and a member for operating said locking member, and means for reciprocating said breech closing unit consisting of an operating lever pivoted at one end to said member which operates said locking member and pivoted intermediate its ends to one end of a link whose other end is pivoted to the receiver below the point where the lever is pivoted to the member which operates said locking member, whereby a link and slider kinematic chain linkage is provided, the links being the said link and the said operating lever and the slider being said breech closing unit reciprocable in said receiver, by means of which linkage a relatively large movement of said lever during the first part of its movement gives a relatively small movement to the reciprocating breech closing unit while the locking member is being moved to disengage its locking surface from said abutment and whereby the breech closing unit serves to guide and control the movements of the operating lever and the link.

ALLEN A. DICKE.

References Cited in the ille of this patent UNITED STATES PATENTS Number Name Date 472,795 Mannlicher Apr. 12, 1892 853,438 Browning May 14, 1907 1,019,937 Whittier Mar. 12, 1912 1,228,827 Saaleld June 5, 1917 1,520,515 Storer Dec. 23, 1924 2,125,571 Jacobson Aug. 2, 1938 2,334,798 Swebilius Nov. 23, 1943 2,386,543 Collins Oct. 9, 1945 2,485,155 Koucky Oct. 18, 1949 

